Thread: probability

Originally Posted by jojo_jojo

An elevator with two passengers stops at the second, third, and fourth floors. If it is equally likely that a passenger gets off at any of the three floors, what is the probability that the passengers get off at different floors?
Thanks.

Pr(passengers get off at different floors) = 1 - Pr(passengers get off at the same floor).

Pr(passengers get off at different floors) = 1 - Pr(passengers get off at the same floor)
So, Pr(passengers get off at the same floor) = 2/6
Therefore, 1 -2/6 = 4/6 = 2/3